:root {
  --bg: #f4f6f9;
  --card: #ffffff;
  --border: #e3e7ed;
  --border-strong: #d3d9e2;
  --text: #1e2530;
  --text-mid: #5b6675;
  --text-mute: #8b95a3;
  --accent: #2563eb;
  --accent-soft: #eaf1fe;
  --danger: #d92d20;
  --danger-soft: #fef3f2;
  --ok: #067647;
  --radius: 12px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
}

.wrap { width: 100%; max-width: 960px; margin: 0 auto; padding: 0 20px; }

/* ---------- header ---------- */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  padding: 26px 0 22px;
}
.site-header h1 { margin: 0; font-size: 22px; font-weight: 650; letter-spacing: .3px; }
.site-header .sub { margin: 6px 0 0; color: var(--text-mute); font-size: 13px; }

/* ---------- tabs ---------- */
.tabs {
  display: flex;
  gap: 4px;
  margin: 22px 0 16px;
  background: #eaeef4;
  padding: 4px;
  border-radius: 10px;
  overflow-x: auto;
}
.tab {
  flex: 1;
  min-width: max-content;
  padding: 9px 14px;
  border: 0;
  background: transparent;
  color: var(--text-mid);
  font-size: 14px;
  font-family: inherit;
  border-radius: 7px;
  cursor: pointer;
  transition: background .15s, color .15s;
  white-space: nowrap;
}
.tab:hover { color: var(--text); }
.tab.is-active { background: #fff; color: var(--accent); font-weight: 600; box-shadow: 0 1px 2px rgba(16,24,40,.06); }

.panel { display: none; }
.panel.is-active { display: block; animation: fade .18s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(3px); } to { opacity: 1; transform: none; } }

/* ---------- card ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: 0 1px 2px rgba(16,24,40,.04);
}
.card-hd {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}
.card-hd h2 { margin: 0; font-size: 16px; font-weight: 650; }
.tag {
  font-size: 12px;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 3px 9px;
  border-radius: 20px;
  font-family: var(--mono);
}

/* ---------- dropzone ---------- */
.dropzone {
  border: 2px dashed var(--border-strong);
  border-radius: var(--radius);
  padding: 34px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  background: #fbfcfe;
}
.dropzone:hover, .dropzone:focus-visible { border-color: var(--accent); background: var(--accent-soft); outline: none; }
.dropzone.is-over { border-color: var(--accent); background: var(--accent-soft); }
.dz-icon { font-size: 30px; line-height: 1; }
.dz-main { margin-top: 10px; font-size: 14px; }
.dz-main strong { color: var(--accent); }
.dz-sub { margin-top: 6px; font-size: 12px; color: var(--text-mute); }

/* ---------- file info ---------- */
.file-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-top: 14px;
  padding: 11px 14px;
  background: #f7f9fc;
  border: 1px solid var(--border);
  border-radius: 9px;
}
.fi-left { display: flex; flex-direction: column; min-width: 0; }
.fi-name { font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.fi-size { font-size: 12px; color: var(--text-mute); font-family: var(--mono); }

/* ---------- progress ---------- */
.progress { display: flex; align-items: center; gap: 12px; margin-top: 14px; }
.progress .bar { flex: 1; height: 6px; background: #e9edf3; border-radius: 99px; overflow: hidden; }
.progress .bar i { display: block; height: 100%; width: 0; background: var(--accent); border-radius: 99px; transition: width .1s linear; }
.progress .pct { font-family: var(--mono); font-size: 12px; color: var(--text-mid); min-width: 42px; text-align: right; }

/* ---------- buttons ---------- */
.actions { display: flex; align-items: center; gap: 16px; margin-top: 18px; flex-wrap: wrap; }

.btn {
  padding: 8px 16px;
  border: 1px solid var(--border-strong);
  background: #fff;
  color: var(--text);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  cursor: pointer;
  transition: background .15s, border-color .15s, opacity .15s;
  white-space: nowrap;
}
.btn:hover { background: #f5f7fa; }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover:not(:disabled) { background: #1d4fd7; }
.btn-primary:disabled { background: var(--accent); }
.btn-ghost { border-color: transparent; background: transparent; color: var(--text-mid); }
.btn-ghost:hover { background: #eef1f6; color: var(--text); }
.btn-sm { padding: 5px 11px; font-size: 13px; }

.inline-check { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; color: var(--text-mid); cursor: pointer; }
.inline-check input { accent-color: var(--accent); cursor: pointer; margin: 0; }
.inline-check em { font-style: normal; color: var(--text-mute); font-size: 12px; }

/* ---------- results ---------- */
.results { margin-top: 20px; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.res-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border);
}
.res-row:last-of-type { border-bottom: 0; }
.res-label { width: 58px; flex: none; font-size: 12px; font-weight: 600; color: var(--text-mid); font-family: var(--mono); }
.res-value { flex: 1; min-width: 0; }
.res-value code {
  display: block;
  font-family: var(--mono);
  font-size: 13px;
  word-break: break-all;
  color: var(--text);
  user-select: all;
}
.res-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 14px;
  background: #f7f9fc;
  font-size: 12px;
  color: var(--text-mute);
  font-family: var(--mono);
}

/* ---------- io (编解码区) ---------- */
.opt-row { display: flex; flex-wrap: wrap; gap: 18px; margin-bottom: 16px; }

.io { display: grid; grid-template-columns: 1fr auto 1fr; gap: 14px; align-items: stretch; }
.io-col { display: flex; flex-direction: column; min-width: 0; }
.io-hd {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12px; color: var(--text-mid); margin-bottom: 6px; height: 26px;
}
.io-col textarea {
  flex: 1;
  min-height: 190px;
  resize: vertical;
  padding: 12px 14px;
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1.7;
  color: var(--text);
  background: #fbfcfe;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
  word-break: break-all;
}
.io-col textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); background: #fff; }
.io-col textarea[readonly] { background: #f7f9fc; }
.io-mid { display: flex; flex-direction: column; justify-content: center; gap: 8px; }

.msg {
  margin-top: 14px;
  padding: 10px 14px;
  border-radius: 9px;
  font-size: 13px;
  background: var(--danger-soft);
  border: 1px solid #fecdca;
  color: var(--danger);
  word-break: break-all;
}
.msg.is-ok { background: #ecfdf3; border-color: #abefc6; color: var(--ok); }

/* ---------- footer ---------- */
.site-footer {
  margin-top: 32px;
  padding: 20px 0 28px;
  color: var(--text-mute);
  font-size: 12px;
  text-align: center;
}

/* ---------- responsive ---------- */
@media (max-width: 720px) {
  .io { grid-template-columns: 1fr; }
  .io-mid { flex-direction: row; justify-content: flex-start; flex-wrap: wrap; }
  .tabs { flex-direction: column; }
  .tab { text-align: left; }
  .card { padding: 18px 16px; }
  .res-row { flex-wrap: wrap; }
  .res-value { flex-basis: 100%; order: 3; }
}

main.wrap { flex: 1 0 auto; }